Sound producing mechanism



Feb. 13, 1934. w, A, EATON 1,947,336

SOUND. JRODUC ING MECHAN I SM Filed May 4, 1932 I N V EN TOR5 PatentedFeb. 13, l1934 SOUND PRODUCING MECHANISM Wilfred A. Eaton, Pittsburgh,Pa., assigner to Bendix Westinghouse Automotive All' Brake Company,Pittsburgh, Pa., a corporation of Delaware Application May 4, 1932.Serial No. 609,225

6 Claims.

The present invention relates to sound-producing devices and moreparticularly to such devices which are adapted to be operated bydifferences in fluid pressure.

An object of the invention is to provide a soundproducing device, suchas a horn, which may be operated by a fluid under pressure, such ascompressed air or the exhaustl gases of an internal combustion engine.

A further object of the invention is to pro-l vide a sound-producingdevice such as a horn, which may be operated by suction which may beprovided by connecting parts of the device to the intake manifold of aninternal combustion engine.

A still further object of the invention is to provide a sound-producingdevice operable by differences of fluid pressure and including meanswhereby the volume of fluid under pressure supplied to thesound-producing device may be varied.

.A still further object of the invention is to provide a sound-producingdevice which may be so operated, at the will of the operator, as toproduce sounds of different tones.

A further object is to provide a sound-producing device which willcomprise a minimum number of parts, which parts are of simple design andconstruction, whereby an inexpensive and rugged structure is produced.

Other objects and features of novelty of the invention will appear moreclearly from the following detailed description taken in connection withthe accompanying drawing, which illustrates one embodiment of theinvention. It is to be expressly understood, however. that the drawingis for purposes of illustration only and is not designed as a definitionof the limits of the invention, rference being had for this purpose tothe appended claims.

Referring to the drawing:

Fig. 1 is a view, partly in section, of a soundproducing deviceaccording to the invention.

Fig. 2 is a sectional view of parts of a soundproducing device accordingto the invention and including certain modifications.

Fig. 3 is a sectional view of parts of a soundproducing device accordingto the invention and including certain further modifications.

Referring to the drawing, and particularly to Fig. 1 thereof, wherein isdisclosed a sectional view of a .sound-producing device embodying vtheprinciples of the present invention, the reference numeral 1 designatesthe bell o1' a horn, which may be attached at its small end, in theusual manner, to a cylindrical horn body member 2. the same having aninternally-threaded end 3, and an externally-threaded central portion 4,which is provided with a suitable internal bore or opening into whichthe small end of the horn bell 1 may be inserted for attachment in anysuitable manner. The central portion 4 is preferably integrally attachedto the cylindrical, marginal portion of body member 2 by a web 5. Formedon the internal circumference of the horn body member 2 and extendingradially toward the center thereof is an annular ridge 6. the samebeingprovided for a purpose which will appear hereinafter.

Disposed within the horn body member 2 is a 70 diaphragm` member 7, thesame being formedV with a central opening whereby it is received on thecentral portion 4 of the horn body members. Washer 8 and nut 9 areprovided for maintaining diaphragm 7 in place, said nut 9 being inter-15 nelly-threaded in order that it may be screwed onto the centralportion 4. The construction and arrangement of the parts described aboveis such that when diaphragm 7 is in normal position, the marginal edgethereof is exactly opposite the 80 center of ridge 6 formed on member 2and is spaced therefrom by only a very slight air-gap. Such marginaledge is, of course, entirely free, the diaphragm being supported only atits center. A suitable cover member 10 is provided, the 86 same beingscrew-threaded to the end 3 of the body member 2.

With the construction as described and illustrated it will be seen thattwo chambers 11 and 12 are provided within the'hornbody, such cham- 90bers being separated by the diaphragm 'l and being connected only by thesmall air-gap between diaphragm 7 and ridge 6. 'As shown in the drawingthe horn bell 1 is in open communication with the chamber 12.

' Means are provided for actuating the horn, such means comprising athreaded opening 13 formed in the body member 2 and which may beconnected by suitable tubing to an air compressor or to the exhaustmanifold or intake manifold of an internal combustion engine. Opening 13is in open communication with chamber 11 and it is important to notethat opening 13 and horn bell 1 are in communication with differentchambers, such construction being necessary for proper operation of thedevice.

4In operation, if a fluid under pressurasuch as compressed air, isemployed, the same is admitted to chamber 11 through opening 13, and insuch chamber will exert a pressure on diaphragm 5'. Due to the fact thatdiaphragm 7 is rigidly mounted only at its central portion andthemarginal edge thereof is almost in contact with ridge' 6, the edge ofsuch diaphragm will act, in effect, as a piston and, due t6 theflexibility of the diaphragm, moves downwardly as viewed in the drawing,Such movement, under continued pressure, will continue as long as theedge of the diaphragm is opposite the top of ridge 6, there being atthis time insufficient space therebetween to permit any appreciablepassage of air. As soon as the edge of diaphragm 7 passes the top ofridge 6 a large, annular space will be opened between diaphragm 7 andthe body member 2. Air under pressure will now flow through saidenlarged annular fspace from chamber 11 into chamber 12 and cause amomentary build-up of pressure therein and a momentary drop in pressurein chamber 11. Due to the momentary rise in pressure in chamber 12 therewill be a rushof air through the horn bell 1. The momentary Areductionin pressure in chamber 11 causes the resilience of the diaphragm toreturn the same to its normal position, closingthe annular opening atits edge and permitting pressure to build up again in chamber 11. At thesame time the rush-of air through the horn bell l is accompaniedby alowering of pressure in chamber 12 and the cycle is ready to vberepeated. It will be appreciated thatthe above variations in thepressure of the air column-in the horn bell 1 Will occur at an audiblefrequency-,. and thus produce a sound. "a,

If it is desired to use suction'or operating thei horn, the opening 13may be connected to the intake manifold of an internal combustionengine. In this case the operation willbe reversed, the suction causingevacuation of chamber 11, whereby diaphragm '7 will move toward or intothat chamber until the edge of the diaphragm passes ridge 6, at whichtime air in chamber 12 will flow into chamber 11 causing a build-up ofpressure vtherein and causing diaphragm 'l'. to return to its centralposition, when the same operation will be repeated.

Means are provided for varying the tone of the sound produced by thedevice described hereinbefore, and one form which such means may take isdisclosed in Fig. 2 of the drawing. Referring particularly to thisiigure it willbe seen that a sound-producing device similar to thatdisclosed in Fig. 1 has been provided, the same having the horn bell l,horn body member 5, cover 10, diaphragm 7 and pressure-fluid hoseattachment means 13, all as described hereinbefore in connection withFig. 1. According to the present modification, however, a. plug 14 isprovided, the same being disposed in the pressure-fluid hose attachmentmeana, which, as disclosed, is preferably formed as a threaded opening13 in the horn body member 5. Plug 14 is provided with a plurality ofopenings 15 extending therethrough and may be threaded on its externalperiphery to facilitate securing the same in position in the threadedopening 13.

A second means for varying the tone of the sound produced by thesound-producing device is disclosed in Fig. 3, the same comprising 'acylindrical plug 16 rotatably disposed in the horn body member 5 andhaving its axis extending at right angles lto that of the threadedopening 13. The plug 16 is provided with a passage 17, the axis of thesame extending at right angles to the axis of the plug. Any suitablemeans, exterior to the horn body member, may be provided for rotatingplug 16. Obviously plug 16 may, at the will of the operator, be sodisposed as to allow free passage of fluid under pressure from opning 13to chamber 1li or may be so adjusted as to allow the passage of anydesired volume 4of pressure fluid, or, if desired, be so adjusted as tocompletely shut of the passage of uid.

It will be apparent to those skilled in the art that if it is desired toVary the tone of the sound produced by the device hereinbeforedescribed, the plug 14 as disclosed in Fig. 2 maybe screwed into theopening l after first removing the hose connected therein. The placingof the plug in the opening will obviously decrease the volume of fluidunder pressure admitted into chamber'll 90 and will therefore give adifferent tone to the sound produced by the horn'. VThe device disclosedin Fig. 3 provides a means whereby an innitevariety of tones may beproduced at the will of the operator. Obviously the adjustment of plug16 will vary the volume of fluid under pressure which may pass fromopening 13 to chamber 11 therebyallowing the operator to vary' the toneof the horn at will.` y

While different embodiments ofthe present invention have beenillustrated and described, it is to be understood that the same may beembodied in various other forms, and that changes in the design orconstruction may be made without departing from the spirit of theinvention. Reference will therefore be had to the appended claims for adenition of the limits of the invention.

What 1s claimed is:

1. A sound-producing device adapted tp be operated by diierences influid pressure, compris- -ing a body member, means dividing said bodymember into two chambers, a li'orn device extending through saiddividing means and opening into one of said chambers, means connectingthe other of said chambers to a source of fluid pressure, said dividingmeans being so formed as to provide an annular passage between saidchambers.

o 2. A sound-producing device adapted to be operated by diierences offluid pressure, comprising a body member having a central portion vforreceiving a horn bell, a diaphragm mounted at its center on said centralportion and having its marginal edge free, a ridge formed on said bodymember, said ridge cooperating with said diaphragm and definingtherewith two chambers, said chambers being connected by an nannularpassage between said diaphragm and said ridge, and means in said bodymember for; admitting fluid pressure to one of said chambers.

3. A sound producing device adapted to be operated by differences ofduid -pressure, comprising a body member having a central projectingportion, a diaphragm secured to said projecting portion and dividingsaid body member into two chambers, a horn bell carried by saidprojecting portion and communicating with one of said chambers and meansfor creating a pressure in the other of said chambers diierent from thatin said rst named chamber.

4. A sound producing device adapted to be operated by diierences iniiuid pressure, comprising a body member, a diaphragm secured at itscentral portion to said body member and dividing said body member intotwo chambers, the periphery of said diaphragm being spaced from saidbody member to provide restricted communication between said chambers,and two conduits formed in the same side of said body mem- 150 ber andcommunicating with said` chambers respectively, one of said conduitsextending through said diaphragm.

5. A sound producing device adapted to be operated by diiierences iniluid pressure, comprising a body member, a diaphragm secured at itscentral portion to said body member and dividing said body member intotwo chambers, the periphery of said diaphragm being spaced from saidbody member to provide restricted communication between said chambers, aconduit communicating with one of said chambers and with a horn bell anda second conduit communicating with the other of said chambers and witha source of different pressure than that in said nrst mentioned chamber.

r6. A sound producing device adapted to be operated by differences influid pressure, comprising a body member having a hollow centralportion, a horn bell secured in saidhollow portion, a diaphragm in saidbody member surrounding said hollow portion and rigidly secured there-WILFRED A. EA'roN.

